package at.chl.genetic.function.math.random;

import java.io.UnsupportedEncodingException;
import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;

public class MathRandomUtil {
	
	public static final long MAX_RANDOM_VALUE=1024;//Long.MAX_VALUE/(1000*1000*1000);
	
	public static String createRandomHashCode(String source) {
		
		Long currentTime=System.currentTimeMillis();
		Long random=getRandomLong();
		
		String md5=source+currentTime+random;
		try {
			md5 = createMD5(md5);
		} catch (NoSuchAlgorithmException e) {
			
			e.printStackTrace();
		} catch (UnsupportedEncodingException e) {
			
			e.printStackTrace();
		}
		
		return md5;

	}
	
	private static String convertToHex(byte[] data) {
        StringBuffer buf = new StringBuffer();
        for (int i = 0; i < data.length; i++) {
        	int halfbyte = (data[i] >>> 4) & 0x0F;
        	int two_halfs = 0;
        	do {
	        	if ((0 <= halfbyte) && (halfbyte <= 9))
	                buf.append((char) ('0' + halfbyte));
	            else
	            	buf.append((char) ('a' + (halfbyte - 10)));
	        	halfbyte = data[i] & 0x0F;
        	} while(two_halfs++ < 1);
        }
        return buf.toString();
    }
 
	public static String createMD5(String text) 
	throws NoSuchAlgorithmException, UnsupportedEncodingException  {
		MessageDigest md;
		md = MessageDigest.getInstance("MD5");
		byte[] md5hash = new byte[32];
		md.update(text.getBytes("iso-8859-1"), 0, text.length());
		md5hash = md.digest();
		return convertToHex(md5hash);
	}

	
	
	public static long getRandomLong(long range){
		return (long)(Math.random()*range);
	}
	
	public static long getRandomLong(){
		return (long)(Math.random()*MAX_RANDOM_VALUE);
	}
}
